plasma lipid

Triacylglycerols, free and esterified cholesterol and phospholipids, present in lipoproteins in blood plasma.

Chylomicrons consist mainly of triacylglycerols and protein; they are the form in which lipids absorbed in the small intestine enter the bloodstream.

Very low-density lipoproteins (VLDL) are assembled in the liver and exported to other tissues, where they provide a source of lipids. Lipid-depleted VLDL becomes low density lipoprotein (LDL) in the circulation; it is rich in cholesterol and is normally cleared by the liver. High-density lipoproteins (HDL) contains cholesterol from LDL and tissues that is returned to the liver. See also hypercholesterolaemia; hyperlipidaemia.

The various plasma lipid classes include triacylglycerols, phospholipids, cholesterol, cholesterol esters, and unesterified fatty acids. Because of their hydrophobic nature, plasma lipids are carried in association with specific plasma proteins, the lipoproteins.